It is increasingly evident that 1) the rate of energy consumption is coupled to CNS function and 2) the cyclic nucleotides as neuro-effectors may play an important role in neuronal excitability. Therefore, any changes in the brain levels of the cyclic nucleo-tides and the energy metabolites may reflect alterations in neural function. These parameters were examined after treatment with the following neurotropic agents: 1) anticonvulsants, 2) convulsants and 3) anesthetics. Major shifts in the balance between energy production and energy utilization were only evident during overt convulsive behavior. The anesthetic, halothane, also affected the profile of the energy metabolites, however the energy status of the tissue was maintained. Cyclic GMP was affected by all three classes of agents, whereas cyclic AMP only changed during the excitable stages of convulsion. These parameters are presently being examined in brains from 'kindled' rats.